Jailed member of the Pussy Riot feminist group Nadezhda Tolokonnikova has been taken to the hospital after she complained of headaches and of suffering from hard work at a Siberian prison colony.

Mordova's Federal prison service spokeswoman Kristina Belousova confirmed that Tolokonnikova, who is serving a two year prison sentence for performing a protest punk prayer against President Vladimir Putin in Christ the Saviour's Cathedral in Moscow, is in hospital but said it was "nothing serious".

Another band member, Yekaterina Samutsevich, who also was sentenced to two years but later released on appeal, claimed Tolokonnikova felt exhausted after working long hours with little sleep.

"They don't allow her to have any rest; she works nearly round the clock," Samutsevich told independent Rain TV on Friday. "She said she feels tired, extremely tired."

Tolokonnikova's husband and street artist Pyotr Verzilov, who founded the Voina art group along with the feminist rocker, dismissed rumours of a specific illness.

"Obviously, the conditions aren't that great, but her lawyer's dealing with it," he told The Associated Press.

In an interview published last week, Tolokonnikova told the independent Novaya Gazeta newspaper that she does not expect clemency from Russian authorities. Putin just does not exist for her, she said. "He is just a blank spot for me."

But she admitted that she misses the freedom to read what she likes inside her Siberian prison colony.

"I am not paying much attention to living conditions," she said in another interview filmed in December. "I'm ascetic, and living conditions matter little for me."